References of "Stanev, Emil"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailCoastal-open ocean exchange in the Black Sea: Observations and modelling
Stanev, Emil; Beckers, Jean-Marie ULg; Lancelot, Christiane et al

in Estuarine Coastal & Shelf Science (2002), 54(3), 601-620

The interaction between physical and biological processes in the areas of continental margins governs the variability of ecosystems. The complexity of processes in these areas requires detailed studies ... [more ▼]

The interaction between physical and biological processes in the areas of continental margins governs the variability of ecosystems. The complexity of processes in these areas requires detailed studies combining modelling and surveying efforts. One promising step in this direction was undertaken in the framework of the EROS 21 project, focusing on the shelf part of the north-western Black Sea. In the present paper, we focus on the results of physical studies aiming to improve the understanding of the fundamental exchange processes in the ocean margins, as well as to quantify some of them in the Black Sea. We illustrate the capabilities of circulation models to reproduce physical processes with different time- and space-scales: coastal waves, internal waves, baroclinic Rossby and topographic waves. Another class of important phenomena in the coastal zone is associated with convection. Sources at the sea surface and in the outflow areas give rise to plume dynamics that play a crucial role in the vertical mixing and provide the mechanism for water-mass formation. Most of the results are illustrated for the shelf part of the Black Sea. The verification of simulations is performed by comparison with survey data, altimeter data from the Topex/Poseidon mission and radiotracer observations. The latter, in combination with simulations from circulation models, are used to trace the penetration of tracers into the intermediate and deep layers. We show that although most Sr-90 is introduced by river runoff, large amounts of this signal penetrate the halocline in the Bosphorus Straits area and along the southern coast. Another important fraction of the river water penetrates the intermediate layers at the shelf edge in the north-western Black Sea. (C) 2002 Elsevier Science Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 56 (8 ULg)
Full Text
Peer Reviewed
See detailVentilation of Black sea’s anoxic waters
Grégoire, Marilaure ULg; Stanev, Emil; Delhez, Géraldine ULg

in Journal of Marine Systems (2001), 31(1-3), 244

The European Inco-Copernicus project was a three-year long international project ŽMay 97–May 2000. financed by the European Commission, combining the expertise and research efforts of scientists from the ... [more ▼]

The European Inco-Copernicus project was a three-year long international project ŽMay 97–May 2000. financed by the European Commission, combining the expertise and research efforts of scientists from the European Union and from the associated and new independent states in the fields of physical and biogeochemical oceanography, limnology and atmospheric science. This project addressed the various mechanisms which control the ventilation of anoxic waters in the Black Sea, as well as the structure and variability of the chemocline. The study was based on the combination of the analysis of relevant hydrographic and chemical data with hydrodynamic and biogeochemical mathematical models. [less ▲]

Detailed reference viewed: 36 (16 ULg)
Full Text
Peer Reviewed
See detailBarotropic and baroclinic oscillations in strongly stratified ocean basins - Numerical study of the Black Sea
Stanev, Emil; Beckers, Jean-Marie ULg

in Journal of Marine Systems (1999), 19(1-3), 65-112

We investigate barotropic and baroclinic oscillations in strongly stratified basins using the Black Sea as a test case. The GHER 3D-model, which has active free surface and temperature and salinity fields ... [more ▼]

We investigate barotropic and baroclinic oscillations in strongly stratified basins using the Black Sea as a test case. The GHER 3D-model, which has active free surface and temperature and salinity fields as scalar state variables produces model results which are then analysed with a focus on barotropic and baroclinic waves at different scales. The model is forced by seasonally variable climatic data and river run-off. High frequency oscillations of the sea level simulated by the model are compared against observations. It is found that phases and amplitudes are simulated realistically. For the density field, long internal gravity waves dominate the solution in the sub-inertial range, The amplitudes of these oscillations increase over the continental slope, which provides an efficient mechanism for mixing in the western Black Sea. It is found that the sea surface oscillations interact with the oscillations in the pycnocline. This interaction could contribute to a modification of the vertical stratification in a long run. The vertical stratification, on its side, jointly with the bottom relief causes different appearances of oscillations over the continental slope and in the basin interior. Changes in the stability of stratification, caused by the seasonal cycle, are thus an important factor modifying wave processes and the resulting internal mixing. (C) 1999 Elsevier Science B.V. All rights reserved. [less ▲]

Detailed reference viewed: 61 (3 ULg)
Full Text
Peer Reviewed
See detailNumerical simulations of seasonal and interannual variability of the Black Sea thermohaline circulation
Stanev, Emil; Beckers, Jean-Marie ULg

in Journal of Marine Systems (1999), 22(4), 241-267

The Black Sea general circulation is simulated by a primitive equation model with active free surface. The forcing is seasonally variable and is based on available climatic data. The model reproduces the ... [more ▼]

The Black Sea general circulation is simulated by a primitive equation model with active free surface. The forcing is seasonally variable and is based on available climatic data. The model reproduces the main features of the Black Sea circulation, including the river discharge effects on the mean sea level and the Bosphorus outflow. Model results show that the simulated sea surface elevation increases in spring over the whole sea, reaching a maximum in the Danube delta area. In the same region, a minimum is observed in winter. The amplitude of the seasonal oscillations (about 8-12 cm over the whole basin) is of the same order of magnitude as the maximum horizontal variations (about 15-18 cm between the coastal areas and the basin interior). This strong signal formed mostly by river discharges, along with the seasonal variability in the other forcing functions and the local dynamics creates a well-pronounced interannual variability. The performance of the model in simulating the seasonal and interannual variability is critically analyzed, with a special attention on the cold intermediate water formation and the circulation in the upper 150 m. The simulations demonstrate that the source of intermediate waters is on the shelf, and that the water mass in the core of cold intermediate layer changes with time as a response to the periodic forcing at sea surface. This type of variability is characterized by pronounced interannual changes, proving that important differences could exist between water mass structure in different years, even when using identical atmospheric forcings each year. (C) 1999 Elsevier Science B.V. All rights reserved. [less ▲]

Detailed reference viewed: 15 (2 ULg)
Full Text
Peer Reviewed
See detailReconnaissance of the main Black Sea's ecohydrodynamics by means of a 3D interdisciplinary model
Grégoire, Marilaure ULg; Beckers, Jean-Marie ULg; Nihoul, Jacques ULg et al

in Journal of Marine Systems (1998), 16(1-2), 85-105

A 3D interdisciplinary model has been used to test the sensitivity of the Black Sea’s ecosystem to physical processes. The hydrodynamical model of the general circulation has been built up, using the GHER ... [more ▼]

A 3D interdisciplinary model has been used to test the sensitivity of the Black Sea’s ecosystem to physical processes. The hydrodynamical model of the general circulation has been built up, using the GHER primitive equation model. A model with 15 km horizontal resolution and 25 vertical levels is used to compute the typical seasonal cycle. The model is forced by climatological monthly mean fields of temperature, salinity and wind stress at the air–sea interface; the river discharges of the Danube, Dnestr and Dnepr are taken into account. An ecosystem model at basin scale is then defined by a nitrogen cycle considering several phytoplankton and zooplankton sizes and including the microbial loop. The ecosystem model is embedded on-line into the 3D hydrodynamical model with a superimposed cycle for the light intensity. This model must be regarded rather as a first tool for testing the coupling of hydrodynamic and ecosystem submodels, while acquiring some preparatory assessment of the effect of physical processes on the ecodynamics. The results display a highly three-dimensional aspect with important horizontal and vertical variations, obviously imparted to the system by the physical processes horizontal and vertical advection, vertical mixing and diffusion, upwelling associated with light limitation at depth and sinking of dead organisms. In this paper, the results are described emphasizing the effects of the hydrodynamic constraints on the space–time distribution of the primary and secondary production. [less ▲]

Detailed reference viewed: 66 (24 ULg)
Full Text
See detailCoupled Hydrodynamic Ecosystem model of the Black Sea at basin scale. First results.
Grégoire, Marilaure ULg; Beckers, Jean-Marie ULg; Nihoul, Jacques ULg et al

in Ozsoy, Emin; Mikaelyan, Alexander (Eds.) Sensitivity to change : Black Sea, Baltic Sea and North Sea (1997)

Detailed reference viewed: 41 (13 ULg)
Peer Reviewed
See detailPreliminary study of the Black Sea's plankton bloom
Grégoire, Marilaure ULg; Beckers, Jean-Marie ULg; Nihoul, Jacques ULg et al

in Bulletin de la Société Royale des Sciences de Liège (1996), 65(1), 91-94

Detailed reference viewed: 37 (12 ULg)